The credentials provided for the SQL source are invalid

Hi,

Last week an automatic refresh on a Power BI Data Model suddenly started failing. The Manager of the Team has left and on day before it failed her windows account was put into quarantine so I thought that may be the issue. However, we restored her account yesterday but today the refresh is still failing. 

This is the error that the refresh is showing:

There was an error when processing the data in the dataset.

Data source error: {"error":{"code":"DM_GWPipeline_Gateway_InvalidConnectionCredentials","pbi.error":{"code":"DM_GWPipeline_Gateway_InvalidConnectionCredentials","parameters":{},"details":[{"code":"DM_ErrorDetailNameCode_UnderlyingErrorCode","detail":{"type":1,"value":"-2147467259"}},{"code":"DM_ErrorDetailNameCode_UnderlyingErrorMessage","detail":{"type":1,"value":"The credentials provided for the SQL source are invalid. (Source at ########;Daily_Sales_RR.)"}},{"code":"DM_ErrorDetailNameCode_UnderlyingHResult","detail":{"type":1,"value":"-2147467259"}},{"code":"Microsoft.Data.Mashup.CredentialError.DataSourceKind","detail":{"type":1,"value":"SQL"}},{"code":"Microsoft.Data.Mashup.CredentialError.DataSourcePath","detail":{"type":1,"value":"########;Daily_Sales_RR"}},{"code":"Microsoft.Data.Mashup.CredentialError.Reason","detail":{"type":1,"value":"AccessUnauthorized"}},{"code":"Microsoft.Data.Mashup.MashupSecurityException.DataSources","detail":{"type":1,"value":"[{\"kind\":\"SQL\",\"path\":\"########;Daily_Sales_RR\"}]"}},{"code":"Microsoft.Data.Mashup.MashupSecurityException.Reason","detail":{"type":1,"value":"AccessUnauthorized"}}],"exceptionCulprit":1}}} Table: DailySales_Daily.

Cluster URI:      WABI-NORTH-EUROPE-K-PRIMARY-redirect.analysis.windows.net

Activity ID:       87dc2ba2-c6e8-4af6-b218-de7e0de8f116

Request ID:      27b576a7-e7a8-b928-8faa-44a459ca8796

Time:    2023-09-14 08:54:22Z

Any help would be greatly appreciated as this has been going on for a week now.